Three partners at a City of London law firm have been hit with the biggest joint fine ever handed out by the Solicitors Disciplinary Tribunal as part of a £70,000 penalty for breaching money-laundering rules.

Clyde & Co, an international law firm that specialises in insurance, maritime and aviation law, was found to have allowed a client bank account to be used as an escrow facility in 2013, which breached professional regulation.

The tribunal fined the three partners – Christopher Duffy, Simon Gamblin and Nick Purnell – £10,000 each. The rest was levied against the firm as a whole.

All three are understood to have admitted breaching the professional rules. The tribunal also found that they had technically failed to adhere to the Money Laundering Regulations 2007.

A statement from the Solicitors Regulation Authority said that the three partners “failed to heed the guidance in the Law Society’s fraudulent financial arrangements warning and/or the warning notice on money laundering, in that they acted as escrow agent in transactions on behalf of a client that had the hallmarks of dubious financial arrangements or investment schemes”.

The regulator added that the firm also “failed to have in place adequate procedures to deal with dormant client balances”.

In a statement given to The Lawyer magazine, the firm said it acknowledged that “the firm and three of its partners did act in breach of the SRA accounts rules and money-laundering regulations, which also led to breaches of certain SRA principles and code”.

It maintained that the mistakes were inadvertent and made honestly. “It is not alleged that the firm or the three partners lacked integrity, probity or trustworthiness, or laundered or misappropriated money,” the statement said.

The SRA has clarified the recent fine levied on Clyde & Co, the City of London law firm that was found to have breached money-laundering regulations. The firm itself was fined £50,000 in addition to three individual partners being fined £10,000 each, bringing the total penalty to £80,000. Earlier reports suggested that the total fine was £50,000.